Oil pump

ABSTRACT

An oil pump includes a motor including a shaft disposed along a center axis, a rotor rotating around the shaft, a stator disposed to face the rotor, a housing accommodating the rotor and the stator, and a pump. The pump includes a pump rotor rotating together with the shaft, and a pump housing including an accommodating portion that accommodates the pump rotor. The pump housing includes a suction port that suctions in oil, a discharge port that discharges oil, and a pressure sensor that detects hydraulic pressure of oil in a partial flow passage allowing communication between the discharge port and the accommodating portion. The pressure sensor is disposed outside the housing of the motor, and the housing includes a wall that blocks electromagnetic waves.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. national stage of PCT Application No. PCT/JP2018/009468,filed on Mar. 12, 2018, and priority under 35 U.S.C. § 119(a) and 35U.S.C. § 365(b) is claimed from Japanese Application No. 2017-057116,filed Mar. 23, 2017; the entire disclosures of each application arehereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an oil pump.

BACKGROUND

In recent years, since an electric oil pump used for a transmission orthe like has been installed in an existing space of a vehicle,restrictions on mounting conditions have been severe, and thusminiaturization is required so that the electric oil pump can beinstalled in various mounting spaces.

Also, there is a concern that the operation of the transmission in ahalf clutch state may become unstable due to hydraulic vibrations of oildischarged from the electric oil pump. In order to eliminate thisconcern, it is conceivable to increase a rotational speed of the oilpump. However, simply raising the rotational speed increases a flow rateof oil, making pressure excessive, and therefore the pressure in thehalf clutch state cannot be maintained.

Meanwhile, Japanese Unexamined Patent Application Publication No.2015-148310 discloses a control device for a continuously variabletransmission which can inhibit amplification of hydraulic vibrationsgenerated in a control valve unit due to hydraulic vibrations of oildischarged from an electric oil pump. In the control valve unit, atorque converter constituting the continuously variable transmission, aforward-reverse switching mechanism, and a plurality of valves forcontrolling respective operations of a belt-type continuously variabletransmission mechanism are provided. The plurality of valves controlsupply and discharge of the oil discharged from the electric oil pump tocontrol operations of a plurality of devices in the continuouslyvariable transmission. When there is a concern that the hydraulicvibrations may be amplified in the control valve unit, the controldevice of the continuously variable transmission raises a line pressureto inhibit the amplification of the hydraulic vibrations.

The control device of the continuously variable transmission describedin Japanese Unexamined Patent Application Publication No. 2015-148310can inhibit amplification of hydraulic vibrations of oil discharged fromthe electric oil pump by raising the line pressure. However, in thecontrol device of the continuously variable transmission described inJapanese Unexamined Patent Application Publication No. 2015-148310,there is no means for directly detecting the line pressure, and the linepressure is indirectly detected from command signals to a line pressuresolenoid valve that controls the line pressure. For this reason, thedetected line pressure may not be accurate.

SUMMARY

Example embodiments of the present disclosure to provide oil pumps eachcapable of accurately detecting hydraulic pressure of oil discharged andcapable of being miniaturized.

An example embodiment of the present disclosure provides a motorincluding a shaft disposed along a center axis extending in an axialdirection, a rotor rotating around the shaft, a stator disposed to facethe rotor, a housing accommodating the rotor and the stator, and a pump.The pump includes a pump rotor rotating together with the shaft tosuction and discharge oil, and a pump housing including an accommodatingportion that accommodates the pump rotor. The pump housing includes asuction port that suctions in oil, a discharge port that discharges oil,and a pressure sensor that detects hydraulic pressure of oil in a flowpassage allowing communication between the discharge port and theaccommodating portion. The pressure sensor is disposed outside thehousing of the motor, and the housing includes a wall that blockselectromagnetic waves.

According to an example embodiment of the present disclosure, it ispossible to provide an oil pump that is able to accurately detecthydraulic pressure of oil discharged from the oil pump and is able to beminiaturized.

The above and other elements, features, steps, characteristics andadvantages of the present disclosure will become more apparent from thefollowing detailed description of the example embodiments with referenceto the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an oil pump according to afirst example embodiment of the present disclosure.

FIG. 2 illustrates a cross-sectional view of the oil pump.

FIG. 3 illustrates a perspective view of the oil pump that shows aninternal structure of a pump cover.

FIG. 4 illustrates a plan view of the oil pump that shows the internalstructure of the pump cover.

FIG. 5 illustrates an exploded perspective view of the pump cover inwhich connectors are attached to respective terminals of a solenoidvalve and a pressure sensor which are attached to the pump cover.

FIG. 6 illustrates an exploded perspective view of the oil pump in whichthe pump cover is attached to a motor provided with a pump body.

DETAILED DESCRIPTION

Hereinafter, oil pumps according to example embodiments of the presentdisclosure will be described with reference to the drawings. However,dimensions, materials, shapes, relative dispositions, etc. ofconstituent components described in example embodiments or shown in thedrawings are not intended to limit the scope of the present disclosureto the contents described, but are merely illustrative examples. Forexample, expressions indicating a relative or definitive dispositionsuch as “in a direction,” “along a direction,” “parallel,” “orthogonal,”“center,” “concentric,” or “coaxial” not only represent such adisposition strictly, but also represent a relatively displaced statewith a tolerance, or an angle and a distance that allow the samefunction to be obtained. For example, expressions indicating that thingsare in the same state such as “identical,” “equal,” and “homogeneous”not only represent an equal state strictly, but also represent a statein which there is a tolerance or a difference with which the samefunction can be obtained. For example, expressions indicating shapessuch as a square shape and a cylindrical shape not only represent shapessuch as a square shape and a cylindrical shape in a geometrically strictsense but also represent shapes including an uneven portion, a chamfer,or the like within a range in which the same effect can be obtained. Onthe other hand, expressions “including,” “equipped with,” “providedwith, “comprising,” or “having” a component are not exclusiveexpressions excluding the presence of other components.

In the drawings, an XYZ coordinate system is shown as athree-dimensional orthogonal coordinate system, as needed. In the XYZcoordinate system, a Z-axis direction is a direction parallel to oneaxial direction of a central axis J shown in FIG. 1. An X-axis directionis a direction parallel to a transverse direction of the oil pump shownin FIG. 1, that is, a vertical direction in FIG. 1. A Y-axis directionis a direction orthogonal to both the X-axis direction and the Z-axisdirection.

In the following description, a positive side (+Z side) in the Z-axisdirection is referred to as a “front side,” and a negative side (−Zside) in the Z-axis direction is referred to as a “rear side.” Also, therear side and the front side are names used merely for the purpose ofexplanation and do not limit actual positional relationships anddirections. In addition, unless otherwise noted, a direction parallel tothe central axis J (Z-axis direction) is simply referred as an “axialdirection,” a radial direction centered on the central axis J is simplyreferred as a “radial direction,” and a circumferential directioncentered around the central axis J, that is, a direction around thecentral axis J (θ direction), is simply referred to as a“circumferential direction.”

Further, in the present specification, the term “extending in the axialdirection” means not only a case of strictly extending in the axialdirection (Z-axis direction), but also a case of extending in adirection inclined at an angle less than 45° with respect to the axialdirection. Also, in the present specification, the term “extending inthe radial direction” means not only a case of extending strictly in theradial direction, that is, in a direction perpendicular to the axialdirection (Z-axis direction), but also a case of extending in adirection inclined by less than 45° with respect to the radialdirection.

First Example Embodiment

FIG. 1 illustrates a perspective view of an oil pump according to afirst example embodiment. FIG. 2 illustrates a cross-sectional view ofessential parts of the oil pump.

The oil pump 1 of the present example embodiment has a motor 20 and apump 3 as shown in FIGS. 1 and 2. The motor 20 has a shaft 41 disposedalong the central axis J extending in the axial direction. The pump 3 ispositioned on one side of the motor 20 in the axial direction, and isdriven by the motor 20 via the shaft 41 to discharge oil. That is, themotor 20 and the pump 3 are provided side by side in the axialdirection. Hereinafter, each component will be described in detail.

<Motor 20>

As shown in FIG. 2, the motor 20 has a housing 21, a rotor 40, the shaft41, a stator 50, and a bearing 55.

The motor 20 is, for example, an inner rotor type motor, the rotor 40 isfixed to an outer circumferential surface of the shaft 41, and thestator 50 is positioned outside the rotor 40 in the radial direction.Also, the bearing 55 is disposed at an end portion of the shaft 41 onthe rear side (−Z side) in the axial direction and rotatably supportsthe shaft 41. In addition, the motor 20 may be an outer rotor type motorin which a coil is disposed around the shaft 41, magnets are disposedoutside the coil, and the magnets rotate.

(Housing 21)

The housing 21 has a thin-walled cylindrical shape with a bottom, andhas a bottom surface portion 21 a, a stator holding portion 21 b, a pumpbody holding portion 21 c, a side wall portion 21 d, and flange portions24 and 25. The bottom surface portion 21 a forms a bottomed part, andthe stator holding portion 21 b, the pump body holding portion 21 c andthe side wall portion 21 d form a cylindrical side wall surface centeredon the central axis J. In the present example embodiment, an innerdiameter of the stator holding portion 21 b is larger than an innerdiameter of the pump body holding portion 21 c. An outer surface of thestator 50, that is, an outer surface of a core back portion 51, whichwill be described below, is fitted into an inner surface of the statorholding portion 21 b. Therefore, the stator 50 is accommodated in thehousing 21. Also, the stator holding portion 21 b and the pump bodyholding portion 21 c of the housing 21 are collectively referred to as awall section 21 e.

The flange portion 24 extends radially outward from an end portion ofthe side wall portion 21 d on the front side (+Z side). On the otherhand, the flange portion 25 extends radially outward from an end portionof the stator holding portion 21 b on the rear side (−Z side). Theflange portion 24 and the flange portion 25 are opposed to each other,and are fastened by fastening means (not shown). Therefore, the motor 20and the pump 3 are sealed and fixed in the housing 21.

For example, a zinc-aluminum-magnesium-based alloy or the like can beused as a material of the housing 21, and specifically, a hot-dipzinc-aluminum-magnesium alloy plated steel plate and a steel strip canbe used. Since the housing 21 is a magnesium-based alloy,electromagnetic waves leaking from the inside of the motor 20 throughthe wall section 21 e of the housing 21 to the outside can beeffectively inhibited. Also, the housing 21 is made of a metal, has ahigh heat conductivity and a large surface area, and thus provides anexcellent heat dissipation effect. In addition, a bearing holdingportion 56 for holding the bearing 55 is provided on the bottom surfaceportion 21 a.

(Rotor 40)

The rotor 40 has a rotor core 43 and rotor magnets 44. The rotor core 43is fixed to the shaft 41 to surround the shaft 41 around the axis (θdirection). The rotor magnets 44 are fixed to an outer surface aroundthe axis (θ direction) of the rotor core 43. The rotor core 43 and therotor magnets 44 rotate together with the shaft 41.

(Stator 50)

The stator 50 surrounds the rotor 40 around the axis (θ direction) androtates the rotor 40 around the central axis J. The stator 50 has a coreback portion 51, tooth portions 52, a coil 53, and an insulator (bobbin)54.

The core back portion 51 has a cylindrical shape concentric with theshaft 41. The tooth portions 52 extend from an inner surface of the coreback portion 51 toward the shaft 41. The plurality of tooth portions 52are provided at equal intervals in the circumferential direction of theinner surface of the core back portion 51. The coil 53 is providedaround the insulator (bobbin) 54, and a conductive wire 53a is woundtherearound. The insulator (bobbin) 54 is attached to each tooth portion52.

(Bearing 55)

The bearing 55 is disposed on the rear side (−Z side) of the rotor 40and the stator 50, and is held by the bearing holding portion 56. Thebearing 55 supports the shaft 41. A shape, a structure, and the like ofthe bearing 55 are not particularly limited, and any known bearing canbe used.

(Shaft 41)

The shaft 41 extends along the central axis J and penetrates the motor20. The front side of the shaft 41 protrudes from the motor 20 andextends into the pump 3. An end portion of the shaft 41 on the frontside is disposed in a discharge port 11 of a pump cover 8, which will bedescribed below. The rear side of the shaft 41 protrudes from the motor20 to be supported by the bearing 55 provided in a bus bar holder 58.

<Pump 3>

The pump 3 is positioned on one side of the motor 20 in the axialdirection, in particular, on the front side (+Z side). The pump 3 isdriven by the motor 20 via the shaft 41. The pump 3 has a pump rotor 4and a pump housing 5. The pump housing 5 has a suction port 9, adischarge port 11 and a pressure sensor 70. Further, the pump housing 5has a pump body 6, a pump cover 8 and a receiving port 12.

(Pump Body 6)

The pump body 6 is fixed in a front side of the housing 21 on the frontside (+Z side) of the motor 20. The pump body 6 has an accommodatingportion 7 which accommodates the pump rotor 4 and has a side surface anda bottom surface positioned on the other side (rear side) of the motor20 in the axial direction. The accommodating portion 7 opens toward thefront side (+Z side) and is recessed toward the rear side (−Z side). Ashape of the accommodating portion 7 viewed in the axial direction is acircular shape.

The pump body 6 has a through hole 6 a penetrating therethrough alongthe central axis J. Both ends of the through hole 6 a in the axialdirection open to allow the shaft 41 to pass through, a front side (+Zside) opening thereof opens to the accommodating portion 7, and a rearside (−Z side) opening thereof opens to the motor 20 side. The throughhole 6 a functions as a bearing that rotatably supports the shaft 41.

(Pump Rotor 4)

The pump rotor 4 is attached to the shaft 41. More specifically, thepump rotor 4 is attached to the front side (+Z side) of the shaft 41.The pump rotor 4 has an inner rotor 4 a attached to the shaft 41 and anouter rotor 4 b surrounding an outer side of the inner rotor 4 a in theradial direction. The inner rotor 4 a has an annular shape. The innerrotor 4 a is a gear having teeth on a radially outer surface thereof.

The inner rotor 4 a is fixed to the shaft 41. More specifically, the endportion of the shaft 41 on the front side is press-fitted into the innerrotor 4 a. The inner rotor 4 a rotates together with the shaft 41 aroundthe axis (θ direction). The outer rotor 4 b has an annular shapesurrounding a radially outer side of the inner rotor 4 a. The outerrotor 4 b is a gear having teeth on a radially inner surface thereof.

The inner rotor 4 a and the outer rotor 4 b engage with each other, andthe outer rotor 4 b rotates as the inner rotor 4 a rotates. That is, thepump rotor 4 is rotated by the rotation of the shaft 41. In other words,the motor 20 and the pump 3 have the same rotational axis. Therefore, anincrease in size of the electric oil pump in the axial direction can beinhibited. Also, as the inner rotor 4 a and the outer rotor 4 b rotate,a volume of the engaged portions between the inner rotor 4 a and theouter rotor 4 b changes. A region where the volume decreases forms apressurized region, and a region where the volume increases forms anegative pressure region. The suction port 10 is disposed on one side(front side) of the negative pressure region of the pump rotor 4 in theaxial direction. Further, the receiving port 12 is disposed on one side(front side) of the pressurized region of the pump rotor 4 in the axialdirection. Here, oil suctioned from the suction port 9 into theaccommodating portion 7 is accommodated in the volume portion betweenthe inner rotor 4 a and the outer rotor 4 b and is sent to the dischargeport 11 side. Then, the oil is discharged from the discharge port 11.

(Pump Cover 8)

The pump cover 8 is attached to the front side (+Z side) of the pumpbody 6 and closes an opening 7 a that opens toward one side (front side)of the accommodating portion 7 in the axial direction. In the exampleembodiment shown in FIGS. 1 and 2, the pump cover 8 has a disc-shapedcover main body portion 8 a that expands in the radial direction, and aprotruding portion 8 b that protrudes from a radial end portion of thecover main body portion 8 a. The cover main body portion 8 a closes theopening 7 a of the housing 7 on the front side (+Z side).

As described above, the pump housing 5 has the pump body 6 and the pumpcover 8, and the pump cover 8 closes the opening 7 a that opens towardone side (front side) of the accommodating portion 7 in the axialdirection. Therefore, after the pump rotor 4 is accommodated in theaccommodating portion 7, the opening 7 a is closed with the pump cover8, and thus ease of assembling the pump housing 5 can be improved.

(Cover Main Body Portion 8 a)

The cover main body portion 8 a has a first stepped portion 8 a 1 and asecond stepped portion 8 a 2 that protrude toward the front side (+Zside) in the axial direction. The first stepped portion 8 a 1 has acylindrical shape, is provided substantially coaxially with the centralaxis J, and is connected to a central axis side end portion of a surface8 a 3 on the front side (+Z side) of the cover main body portion 8 a inthe axial direction. The cover main body portion 8 a has a through hole8 a 4 along the central axis J. The through hole 8 a 4 penetratesbetween both end portions of the pump cover 8 in the axial direction.The shaft 41 passes through the through hole 8 a 4.

The second stepped portion 8 a 2 is provided substantially coaxiallywith the central axis J, and has a cylindrical shape smaller in diameterthan the first stepped portion 8 a 1. The second stepped portion 8 a 2is connected to a central axis side end portion of a surface 8 a 5 onthe front side (+Z side) of the first stepped portion 8 a 1 in the axialdirection. The second stepped portion 8 a 2 has a large diameter holeportion 8 a 6 having a diameter larger than that of the through hole 8 a4 along the central axis J, and one end of the shaft 41 in the axialdirection is disposed in the large diameter hole portion 8 a 6.

The discharge port 11 has a first discharge port 11 a and a seconddischarge port 11 b. In the present example embodiment, the firstdischarge port 11 a is the large diameter hole portion 8 a 6. The seconddischarge port 11 b is provided on a tip side of the protruding portion8 b of the pump cover 8, which will be described in detail below. Thesuction port 10 and the receiving port 12 are provided at the other endportion of the cover main body portion 8 a. The suction port 10 isprovided on a side opposite to the protruding portion 8 b with respectto the central axis J. The receiving port 12 is provided on theprotruding portion 8 b side with respect to the central axis J.

More specifically, as shown in FIGS. 2 and 3, the suction port 10 isprovided at a position facing the negative pressure region of the pumprotor 4 and is curved in the circumferential direction of the centralaxis J to extend in an elongated hole shape. Further, the receiving port12 is provided at a position opposite to the pressurized region of thepump rotor 4 and is curved in the circumferential direction of thecentral axis J to extend in an elongated hole shape. For this reason,the oil suctioned from the suction port 9 can be supplied oversubstantially the entire negative pressure region. Also, all of the oilsupplied from the pressurized region can be received by the receivingport 12.

The suction port 9 communicates with the suction port 10 and opens atone end of the first stepped portion 8 a 1 in the axial direction. Thatis, the suction port 9 is provided across the cover main body portion 8a and the first stepped portion 8 a 1. For this reason, the suction port9 is connected to the negative pressure region of the accommodatingportion 7 via the suction port 10.

The first discharge port 11 a and the receiving port 12 are connectedvia a communication passage 15. In the example embodiment shown in FIG.2, one end side of the communication passage 15 opens to an inner sidesurface of the first discharge port 11 a and the other end side thereofopens to one end side of the receiving port 12 in the axial direction.For this reason, the oil received in the receiving port 12 can flow tothe first discharge port 11 a through the communication passage 15.Also, hereinafter, a flow passage 17 through which the oil flows betweenthe receiving port 12 and the first discharge port 11 a will be referredto as a first flow passage 13.

A control valve 81 is connected to the first discharge port 11 a via amain flow passage 80. The main flow passage 80 supplies the oildischarged from the first discharge port 11 a to the control valve 81.The control valve 81 performs supply and discharge control for the oilsupplied from the main flow passage 80 to, for example, an automatictransmission of a vehicle.

(Protruding Portion 8 b)

As shown in FIGS. 1 and 2, the protruding portion 8 b protrudes from theother radial end portion of the cover main body portion 8 a in adirection perpendicular to the axial direction. A tip of the protrudingportion 8 b is positioned outside the housing 21 of the motor 20 in theradial direction. The protruding portion 8 b has a substantially squareshape when viewed from one side in the axial direction. A solenoidinsertion hole 8 b 1 (see FIG. 5) penetrating in the axial direction isprovided on the tip side of the protruding portion 8 b. An opening thatopens to one side (front side) of the solenoid insertion hole 8 b 1 inthe axial direction is the second discharge port 11 b. Hereinafter, theflow passage 17 allowing communication between the second discharge port11 b and the accommodating portion 7 will be referred to as a secondflow passage 14.

As shown in FIGS. 2, 3 and 4, one end of the second flow passage 14 isconnected to the receiving port 12 and the other end thereof isconnected to the second discharge port 11 b via a solenoid valve 60. Inthe illustrated example embodiment, the second flow passage 14 extendsin a first through hole 14 a and a second through hole 14 b which areprovided in the protruding portion 8 b. The first through hole 14 aextends from the receiving port 12 to the tip side of the protrudingportion 8 b and opens at the tip part of the protruding portion 8 b. Thesecond through hole 14 b extends from an end portion of the protrudingportion 8 b on one side in a lateral direction (a positive side in theY-axis direction) toward the solenoid insertion hole 8 b 1 side andpasses through the solenoid insertion hole 8 b 1, then intersects thefirst through hole 14 a to extend toward a pressure sensor insertionhole 8 b 2 and opens in the pressure sensor insertion hole 8 b 2.Sealing members 16 for closing the respective openings are provided atthe opening of the first through hole 14 a on the tip side of theprotruding portion 8 b and the opening of the second through hole 14 bon one side of the protruding portion in the lateral direction. In theillustrated example embodiment, the sealing members 16 are male screws.

Therefore, the second flow passage 14 passes through a partial flowpassage 14 d in which the first through hole portion 14 a 1, which ispositioned in the first through hole 14 a between an intersectionportion 14 c where the first through hole 14 a and the second throughhole 14 b intersect and the receiving port 12, and the second throughhole portion 14 b 1, which is positioned in the second through hole 14 bbetween the intersection portion 14 c and the solenoid insertion hole 8b 1, are connected. Also, the second through hole portion 14 b 1 isconnected to a second suction port 62 of the solenoid valve 60, whichwill be described in detail below. In addition, a third discharge port63 of the solenoid valve 60 is connected to the second discharge port 11b. Therefore, the second flow passage 14 communicates the receiving port12 with the second discharge port 11 b via the second suction port 62 ofthe solenoid valve 60.

Also, the second flow passage 14 is provided in the pump cover 8through, for example, a cutting operation (for example, drilling). Forexample, after the first through hole 14 a is cut from the tip part ofthe protruding portion 8 b of the pump cover 8 toward the receiving port12 side of the pump cover 8, the second through hole 14 b is cut from anend portion of the outer circumferential portion of the protrudingportion 8 b on the positive side in the Y-axis direction toward thesolenoid insertion hole 8 b 1, the first through hole 14 a, and thepressure sensor insertion hole 8 b 2 sides. Then, the sealing members 16are screwed on and fixed to an opening end portion on the tip side ofthe protruding portion 8 b of the first through hole 14 a and an openingend portion on one side of the protruding portion 8 b of the secondthrough hole 14 b in the lateral direction. Thus, the second flowpassage 14 can be provided on the pump cover 8 by cutting. Therefore,workability of the work of providing the second flow passage 14 insidethe pump cover 8 can be improved.

Thus, the pump cover 8 is configured to have the cover main body portion8 a and the protruding portion 8 b, as shown in FIG. 2. Also, the pumpcover 8 is disposed on one side (front side) of the motor 20 in theaxial direction, and an axial region of the pump cover 8 is disposed ina region different from an axial region of the motor 20. In theillustrated example embodiment, the axial region of the pump cover 8 isdisposed in a region on one side (front side) of the motor 20 in theaxial direction. That is, the axial region of the pump cover 8 does notoverlap the axial region of the motor 20 in the axial direction, and isdisposed at a position not facing the axial region of the motor 20.

For this reason, as compared with a case where the second flow passage14 is provided on the radially outer side of the motor 20, a flowpassage length of the second flow passage 14 can be shortened.Therefore, since the pressure sensor 70 can be disposed in the vicinityof the pump rotor 4 that is a hydraulic pressure source, the pressure ofthe oil discharged from the pump rotor 4 can be detected moreaccurately.

<Solenoid Valve 60>

FIG. 5 is an exploded perspective view showing the pump cover 8 in whicha connector 85 is attached to each terminal of the solenoid valve 60 andthe pressure sensor 70 which are attached to the pump cover 8.

As shown in FIGS. 2 and 5, the solenoid valve 60 is fixed to theprotruding portion 8 b and has a valve housing 64, a drive 66, and asolenoid electrical line 67. The valve housing 64 movably accommodates aspool 68 therein. The drive 66 moves the spool 68 relative to the valvehousing 64. The solenoid electrical line 67 has one end portionconnected to the drive 66 and the other end portion provided with asolenoid side terminal 67 a. The spool 68 extends in the valve housing64 in a longitudinal direction and is movably supported to open andclose the second suction port 62.

The valve housing 64 has the second suction port 62 through which theoil flows in via the second flow passage 14 and the third discharge port63 through which the flowed-in oil is discharged. The second suctionport 62 is opened and closed by the movement of the spool 68. For thisreason, by opening and closing the second suction port 62, the flow ofoil flowing through the second flow passage 14 can be blocked andallowed. That is, the solenoid valve 60 has an opening and closingportion 65 capable of opening and closing the flow passage 17. In theillustrated example embodiment, the solenoid valve 60 has the spool 68capable of opening and closing the second flow passage 14. In addition,when the second suction port 62 is opened, the second suction port 62and the third discharge port 63 communicate with each other. For thisreason, when the second suction port 62 is opened, the oil flowingthrough the second flow passage 14 is discharged from the seconddischarge port 11 b through the second suction port 62 and the thirddischarge port 63. For this reason, the operation of opening and closingthe second flow passage 14 by using the opening and closing portion 65of the solenoid valve 60 makes it possible to flow to the second flowpassage 14 side, some of the oil flowing through the first flow passage13. Therefore, a flow rate of the oil to a supply destination of thepressurized oil supplied from the first discharge port 11 a can beadjusted.

As described above, since the protruding portion 8 b further includesthe solenoid valve 60 connected to the flow passage 17, some of the oilsupplied from the discharge port 11 to a pressurized oil supplydestination (for example, a clutch destination) can flow to the solenoidvalve 60 side. Therefore, for example, when the pressurized oil supplydestination is set to the clutch destination, even if the rotationalspeed of the oil pump 1 is increased from 400 rotations to 1200rotations, for example, the increase in the flow rate of oil supplied tothe clutch can be inhibited. For this reason, the frequency of hydraulicvibrations can be increased and shifted to a frequency for avoidingresonance. Therefore, the pressure in a half clutch state can bemaintained while preventing judders in the half clutch state. Inaddition, since the protruding portion 8 b has the solenoid valve 60,the solenoid valve 60 can be disposed close to the motor 20, and thusenlargement of the entire oil pump 1 can be inhibited.

The drive 66 is, for example, an electromagnetic clutch. In the drive66, when power is supplied to the drive 66, for example, the spool 68 ismoved by the magnetic force generated from the drive 66 to open thesecond suction port 62, and when the power supply to the drive 66 is cutoff, the spool 68 is returned to its original position by a biasingforce of a spring (not shown) to close the second suction port 62.Therefore, by controlling the power supply to the drive 66, a positionof the spool 68 can be adjusted to control the opening and closing ofthe second suction port 62.

The third discharge port 63 opens at one side end portion of the valvehousing 64 in the axial direction. On the other hand, the seconddischarge port 11 b provided in the protruding portion 8 b is an openingon one side (front side) of the solenoid insertion hole 8 b 1 in theaxial direction. The valve housing 64 of the solenoid valve 60 isinserted into the solenoid insertion hole 40b1, and the valve housing 64is fixed to the protruding portion 8 b. The drive 66 extending from theprotruding portion 8 b extends to the motor 20 side. In the illustratedexample embodiment, the solenoid valve 60 extends along the axialdirection of the motor 20 to the other end portion side of the motor 20.For this reason, since the solenoid valve 60 is disposed along the motor20, enlargement of the oil pump 1 can be inhibited.

The valve housing 64 is supported in a state where one end portionthereof in the axial direction is positioned on substantially the sameplane as the second discharge port 11 b. For this reason, the seconddischarge port 11 b and the third discharge port 63 are disposed onsubstantially the same plane, and the second discharge port 11 b and thethird discharge port 63 are connected to be in a communication state.The second discharge port 11 b is connected to an oil pan T capable ofstoring oil. In the illustrated example embodiment, the second dischargeport 11 b communicates with the oil pan T via a tank flow passage 83.

As described above, the solenoid valve 60 is connected to the partialflow passage 14 d in the second flow passage 14 that communicates theaccommodating portion 7 and the second suction port 62. For this reason,some of the oil supplied from the first discharge port 11 a to thepressurized oil supply destination (for example, the clutch destination)can flow to the solenoid valve 60 side. Therefore, for example, in thecase in which the pressurized oil supply destination is the clutchdestination, even if a rotational speed of the oil pump 1 is increased,for example, from 400 rotations to 1200 rotations, an increase in theflow rate of oil supplied to the clutch can be inhibited. For thisreason, a frequency of hydraulic vibrations can be increased and can beshifted to a frequency for avoiding resonance. Therefore, the pressurein the half clutch state can be maintained while preventing judders inthe half clutch state. In addition, since the protruding portion 8 b hasthe solenoid valve 60, the solenoid valve 60 can be disposed close tothe motor 20, and thus enlargement of the entire oil pump 1 can beinhibited.

<Pressure Sensor 70>

As shown in FIG. 1, the pressure sensor 70 is fixed to the protrudingportion 8 b and extends toward the motor 20. In the illustrated exampleembodiment, the pressure sensor 70 is disposed outside the housing 21 ofthe motor 20 and is fixed to the other end side (a negative side in theY-axis direction) of the protruding portion 8 b in the lateraldirection. Therefore, the pressure sensor 70 can be disposed close tothe motor 20. For this reason, enlargement of the oil pump 1 can beinhibited.

As shown in FIG. 5, the pressure sensor 70 has a sensor 72 and anelectrical line holder 74. The sensor 72 detects the hydraulic pressureof the oil. The electrical line holder 74 holds a sensor electrical line75 electrically connected to the sensor 72. The sensor 72 has acylindrical shape, and a male screw portion 72 a is provided on an outercircumferential surface of the sensor 72. A female screw portion towhich the male screw portion 72 a can be screwed is provided in thepressure sensor insertion hole 8 b 2. For this reason, the pressuresensor 70 is fixed to the pump cover 8 by screwing the sensor 72 intothe pressure sensor insertion hole 8 b 2.

As shown in FIG. 4, an opening 14 b 2 is provided on an inner surface ofthe second through hole 14 b in a portion of the pressure sensorinsertion hole 8 b 2 into which the sensor 72 is inserted. The opening14 b 2 communicates with the sensor 72. Thus, the pressure sensor 70 isconnected to the accommodating portion 7 through the first through hole14 a and the second through hole 14 b (flow passage 17). Therefore, thepressure sensor 70 can detect the hydraulic pressure of the oil in thefirst flow passage 13 and the second flow passage 14 via the firstthrough hole 14 a and the second through hole 14 b. More specifically,when the second flow passage 14 is closed by the solenoid valve 60, thepressure sensor 70 can detect the hydraulic pressure of the oil in thefirst flow passage 13. Also, when the second flow passage 14 is openedby the solenoid valve 60, the pressure sensor 70 can detect thehydraulic pressure of the oil in the second flow passage 14.

Thus, the pressure sensor 70 is connected to the flow passage 17. Forthis reason, as compared with the case where the flow passage 17 isconfigured of another component, the number of components of the oilpump 1 can be reduced, and thus an increase of the cost for the oil pump1 can be inhibited. Moreover, since the pressure sensor 70 is connectedto the flow passage 17, the hydraulic pressure of the pressurized oildischarged from the accommodating portion 7 can be accurately detectedby the pressure sensor 70 disposed in the vicinity of the accommodatingportion 7 which is a supply source of the hydraulic pressure.

The sensor 72 of the pressure sensor 70 converts, for example, a changein electrical resistance due to a piezoresistive effect into anelectrical signal. As shown in FIG. 5, the electrical signal istransmitted to a sensor side terminal 75 a via the sensor electricalline 75. The electrical signal transmitted to the sensor side terminal75 a is sent to, for example, an engine controller. The enginecontroller controls operations of the automatic transmission, engine, orthe like of the vehicle, and controls operations of the drive 66 of thesolenoid valve 60 on the basis of the electrical signal from thepressure sensor 70 to control the opening and closing of the secondsuction port 62.

In this way, the sensor 72 of the pressure sensor 70 is fixed to thepressure sensor insertion hole 8 b 2 of the protruding portion 8 b.Also, the electrical line holder 74 of the pressure sensor 70 and thesolenoid valve 60 are disposed adjacent to each other and extend in theaxial direction of the motor 20, as shown in FIGS. 1 and 6. Further, theelectrical line holder 74 and the solenoid valve 60 are disposed in adirection orthogonal to the surface on the rear side of the protrudingportion 8 b in the axial direction. For this reason, since the pressuresensor 70 and the solenoid valve 60 are disposed outside the motor 20 inthe radial direction and along the axial direction, the oil pump 1 canbe miniaturized as compared with the case where the pressure sensor 70and the solenoid valve 60 are disposed to face in different directions.

As shown in FIGS. 5 and 6, the sensor side terminal 75 a and thesolenoid side terminal 67 a are integrally held via the connector 85. Inthe illustrated example embodiment, the solenoid electrical line 67 ofthe solenoid valve 60 extends along a side surface of the valve housing64, and the solenoid side terminal 67 a is disposed at a position on therear side behind the rear side end of the valve housing 64 in the axialdirection.

On the other hand, the sensor electrical line 75 of the pressure sensor70 extends along a side surface of the electrical line holder 74, andthe sensor side terminal 75 a is disposed side by side with the solenoidside terminal 67 a. The sensor side terminal 75 a and the solenoid sideterminal 67 a are inserted into and fixed to the connector 85. Theconnector 85 has a wall section 85 a made of an insulating material. Inthe illustrated example embodiment, the wall section 85 a has a hollowsquare cylinder shape.

Thus, since the sensor side terminal 75 a and the solenoid side terminal67 a are integrally held via the connector 85, the sensor side terminal75 a and the solenoid side terminal 67 a can be put together in oneplace as compared with the case where each of the sensor side terminal75 a and the solenoid side terminal 67 a is held via a separateconnector. Therefore, ease of electrically connecting to the terminalsand wiring the electrical lines connected to the terminals can beimproved.

<Operations and Effects of Oil Pump>

Next, operations and effects of the oil pump 1 will be described. Asshown in FIG. 2, when the motor 20 of the oil pump 1 is driven, the oilsuctioned from the suction port 9 of the pump moves in the accommodatingportion 7 of the pump 3 and is discharged from the first discharge port11 a via the receiving port 12 and the communication passage 15. The oildischarged from the first discharge port 11 a is supplied to the controlvalve 81 via the main flow passage 80.

In the present disclosure, the pressure sensor 70 that detects thehydraulic pressure of the oil in the second flow passage 14 is disposedoutside the housing 21 of the motor 20, and the housing 21 has the wallsection 21 e that blocks electromagnetic waves. For this reason, whenthe motor 20 is driven, the electromagnetic waves generated from themotor 20 may adversely affect the pressure sensor 70. However, bydisposing the pressure sensor 70 outside the housing 21 of the motor 20,the housing 21 can block at least some of the electromagnetic wavesgenerated from the motor 20. For this reason, the adverse effect of theelectromagnetic waves on the pressure sensor 70 is inhibited, and thusthe hydraulic pressure of the oil discharged from the pump 3 can beaccurately detected by the pressure sensor 70.

Also, the electrical line holder 74 of the pressure sensor 70 and thesolenoid valve 60 according to the present example embodiment aredisposed adjacent to each other and extend in the axial direction of themotor 20. For this reason, the electrical line holder 74 and thesolenoid valve 60 can be disposed along the motor 20. Therefore,enlargement of the oil pump 1 can be inhibited.

Also, the pump cover 8 has the first discharge port 11 a, the seconddischarge port 11 b, the first flow passage 13 allowing communicationbetween the first discharge port 11 a and the accommodating portion 7,and the second flow passage 14 allowing communication between the seconddischarge port 11 b and the accommodating portion 7. The second flowpassage 14 is connected to the second suction port 62 of the solenoidvalve 60, and the second discharge port 11 b of the pump cover 8 isconnected to the third discharge port 63 of the solenoid valve 60. Thus,the second flow passage 14 connecting the pump 3 and the solenoid valve60 can be shortened. Therefore, enlargement of the oil pump 1 can beinhibited. Moreover, as compared with the case where the second flowpassage 14 is configured of another member, the number of components canbe reduced and an increase of the cost for the oil pump 1 can becontrolled.

Also, the solenoid valve 60 connects between any one of the firstdischarge port 11 a and the second discharge port 11 b and theaccommodating portion 7 via the partial flow passage 14 d. For thisreason, the oil discharged from the accommodating portion 7 can bedischarged from any one of the first discharge port 11 a and the seconddischarge port 11 b via the solenoid valve 60. Therefore, some of theoil supplied from the other one of the first discharge port 11 a and thesecond discharge port 11 b to the pressurized oil supply destination(for example, the clutch destination) can flow to the solenoid valve 60side.

The first discharge port 11 a can be connected to the main flow passage80 that supplies the oil discharged from the first discharge port 11 ato the control valve 81, and the second discharge port 11 b can beconnected to the oil pan T capable of storing oil. The solenoid valve 60connects the accommodating portion 7 with the second discharge port 11 bvia the partial flow passage 14 d. For this reason, when the partialflow passage 14 d is opened by the solenoid valve 60, some of the oilsupplied from the discharge port 11 to the control valve 81 can flow tothe solenoid valve 60 side. Also, when the partial flow passage 14 d isclosed by the solenoid valve 60, all of the oil supplied from thedischarge port 11 can be supplied to the control valve 81. That is, byopening and closing the partial flow passage 14 d by using the solenoidvalve 60, a flow rate of the oil supplied to the control valve 81 can beadjusted.

While example embodiments of the present disclosure have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present disclosure. The scope of the presentdisclosure, therefore, is to be determined solely by the followingclaims.

1-13. (canceled)
 14. An oil pump, comprising: a motor including a shaftdisposed along a center axis extending in an axial direction, a rotorrotating around the shaft, a stator disposed to face the rotor, and ahousing accommodating the rotor and the stator; and a pump including apump rotor rotating together with the shaft to suction and dischargeoil, and a pump housing including an accommodating portion thataccommodates the pump rotor; wherein the pump housing includes a suctionport that suctions in oil, a discharge port that discharges oil, and apressure sensor that detects hydraulic pressure of oil in a flow passageallowing communication between the discharge port and the accommodatingportion; the pressure sensor is disposed outside the housing of themotor; and the housing includes a wall that blocks electromagneticwaves.
 15. The oil pump according to claim 14, wherein the pump isdisposed on one side of the motor in an axial direction thereof; and thepump housing includes a pump body including the accommodating portionthat accommodates the pump rotor and further includes a side surface anda bottom surface positioned on another side of the motor in the axialdirection, and a pump cover closing an opening that opens at one side ofthe accommodating portion in the axial direction.
 16. The oil pumpaccording to claim 15, wherein the pump cover includes a protrudingportion which protrudes outward beyond an outer circumference of themotor in a radial direction; and the pressure sensor is fixed to theprotruding portion.
 17. The oil pump according to claim 16, wherein theprotruding portion includes the flow passage allowing communicationbetween the discharge port and the accommodating portion; and thepressure sensor is connected to the flow passage.
 18. The oil pumpaccording to claim 17, wherein the protruding portion further includes asolenoid valve connected to the flow passage.
 19. The oil pump accordingto claim 18, wherein the solenoid valve is fixed to the protrudingportion and extends to a side of the motor.
 20. The oil pump accordingto claim 19, wherein the pressure sensor includes a sensor electricalline electrically connected to the pressure sensor; the sensorelectrical line includes a sensor side terminal at one end portionthereof; the solenoid valve includes a valve housing in which a spool ismovably accommodated, a drive moving the spool relative to the housing,and a solenoid electrical line including one end portion connected tothe drive and another end portion provided with a solenoid sideterminal; and the sensor side terminal and the solenoid side terminalare integrally held via a connector.
 21. The oil pump according to claim20, wherein the pressure sensor includes a sensor which detects thehydraulic pressure of the oil, and an electrical line holder which holdsthe sensor electrical line electrically connected to the sensor; and theelectrical line holder of the pressure sensor and the solenoid valve aredisposed adjacent to each other and extend in the axial direction of themotor.
 22. The oil pump according to claim 18, wherein the solenoidvalve includes an opening and closing portion.
 23. The oil pumpaccording to claim 22, wherein the discharge port includes a firstdischarge port and a second discharge port; and the solenoid valveconnects between any one of the first discharge port, the seconddischarge port, and the accommodating portion via the flow passage. 24.The oil pump according to claim 23, wherein the pump is attachable to acontrol valve that performs supply and discharge control of the oil; thefirst discharge port is connectable to a main flow passage whichsupplies the oil discharged from the first discharge port, to thecontrol valve; the second discharge port is connectable to an oil panthat stores the oil; and the solenoid valve connects the accommodatingportion and the second discharge port via the flow passage.
 25. The oilpump according to claim 24, wherein the solenoid valve includes a secondsuction port through which pressurized oil discharged from the pump issuctioned, and a third discharge port through which the oil isdischarged to the oil pan side that stores the pressurized oil; the pumpcover includes the first discharge port, the second discharge port, afirst flow passage allowing communication between the first dischargeport and the accommodating portion, and a second flow passage allowingcommunication between the second discharge port and the accommodatingportion; the second flow passage is connected to the second suction portof the solenoid valve; and the second discharge port of the pump coveris connected to the third discharge port of the solenoid valve.
 26. Theoil pump according to claim 15, wherein the second flow passage extendsin a direction orthogonal to the axial direction of the motor, andpenetrates from inside to an outer circumferential portion of the pumpcover; and a seal is disposed at an opening end portion of the secondflow passage that opens to the outer circumferential portion of the pumpcover.